Shippagan
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Shippagan clear sky chart from 2005-11-05 to 2017-12-04.

This page is a summary of past forecasts. Even though it's based only on forecasts, some people use these pages as clue to a site's climate. But climate data based on actual observation should be preferred (if you can find it!).

Cloud, Transparency and Seeing forecasts are summarized individually. But because good observing conditions require a combination of minimum cloud cover, transparency and seeing, the individual forecast summaries can be difficult to interpret. The observing conditions section counts the combinations of conditions needed for common types of astronomical observation.

Observing Conditions

The following tables count the occurrence of the combinations of forecast and darkness conditions needed for different observations. Conditions are rated by by what percentage of the hours the observation would likely be attempted are usable.
Observation TypeMinimum conditions for hour to be usableOut of hours
Clear of CloudsTransparencySeeingSky Brightness
Planetary:50%(no limit)Average(no limit)Nighttime Hours
Deep Sky:70%Average(no limit)5.9Nighttime Hours
CCD Imaging:70%Below AveragePoor(no limit)Nighttime Hours

Percentages are of nighttime hours per month, or per year, when a particular observing conditions was met. Deep Sky percentages never exceed 50% because the moon is up half the time. Deep sky percentages are much lower for charts at high latitudes because of fewer dark hours in the summer.

Overall

PlanetaryData
Pts
Deep Sky
Max 60%
Data
Pts
Both Planetary and Deep Sky
Max 60%
Data
Pts
Either Planetary or Deep SkyData
Pts
CCD ImagingData
Pts
Night
28%
15072
12%
47738
6%
15032
35%
15032
15%
34788

By Month

MonthDays of MonthPlanetaryData
Pts
Deep Sky
Max 60%
Data
Pts
Both Planetary and Deep Sky
Max 60%
Data
Pts
Either Planetary or Deep SkyData
Pts
CCD ImagingData
Pts
January1st to 15thNight
14%
750
8%
2685
1%
746
22%
746
8%
2121
January16th to endNight
20%
781
15%
2667
4%
781
34%
781
13%
1897
February1st to 15thNight
25%
704
11%
2286
3%
701
35%
701
16%
1621
February16th to endNight
26%
631
11%
2051
4%
631
35%
631
12%
1529
March1st to 15thNight
25%
719
17%
2010
7%
719
34%
719
17%
1473
March16th to endNight
25%
768
17%
2112
6%
768
34%
768
19%
1510
April1st to 15thNight
30%
549
14%
1755
8%
549
35%
549
16%
1258
April16th to endNight
31%
540
16%
1620
9%
540
37%
540
20%
1134
May1st to 15thNight
35%
540
10%
1484
6%
540
38%
540
19%
1090
May16th to endNight
32%
516
10%
1451
4%
515
37%
515
19%
1068
June1st to 15thNight
38%
360
6%
1260
4%
360
39%
360
14%
905
June16th to endNight
40%
360
5%
1260
4%
360
41%
360
15%
906
July1st to 15thNight
52%
340
10%
1190
9%
340
54%
340
22%
763
July16th to endNight
46%
454
10%
1313
7%
426
48%
426
20%
918
August1st to 15thNight
50%
539
9%
1600
8%
535
52%
535
23%
1104
August16th to endNight
49%
573
15%
1739
10%
573
53%
573
25%
1153
September1st to 15thNight
37%
540
15%
1800
9%
540
45%
540
22%
1169
September16th to endNight
39%
717
21%
2007
12%
717
47%
717
30%
1269
October1st to 15thNight
31%
720
17%
2160
7%
720
40%
720
23%
1450
October16th to endNight
21%
772
13%
2367
4%
772
29%
772
14%
1756
November1st to 15thNight
23%
805
14%
2663
6%
805
32%
805
13%
1949
November16th to endNight
20%
825
9%
2730
3%
825
27%
825
9%
2165
December1st to 15thNight
12%
769
7%
2648
1%
769
19%
769
6%
2185
December16th to endNight
12%
800
7%
2880
1%
800
19%
800
6%
2395

Individual Forecasts

The length of each colored bar in the "occurrence of each Forecast" column is proportional to the number of times the chart forecast that color. The percentages are of the total number of hours per month, or per year, with a particular forecast. The colors as the same as those used in clear sky charts.

Note: Transparency probabilities are only counted for those hours that have 30% or less cloud cover. Seeing probabilities are only counted for those hours that have 80% or less cloud cover. If that's too tricky, try Observing Conditions instead.

Overall

Occurrence of each ForecastData
Points
Cloud CoverDay
18%8%36%5%3445%7%33%
48772
Night
19%9%36%5%3445%6%30%
47894
TransparencyDay
49%6%14%19%8%
48446
Night
54%5%11%18%8%
47738
SeeingDay
23%8%27%25%11%3
7326
Night
23%9%28%26%9%1
15073

By Month

Percentage Cloud Cover NE (2006-)
Color Meanings:
Overcast 90% covered 80% covered 70% covered 60% covered 50% covered 40% covered 30% covered 20% covered 10% covered Clear
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
14%14%5%8%8%36%6%45%21%
1253
16th to endDay
14%9%36%6%36%5%48%29%
1555
February1st to 15thDay
11%11%47%6%45%5%6%7%30%
1575
16th to endDay
15%13%5%6%6%35%336%30%
1422
March1st to 15thDay
16%8%35%6%2435%7%35%
1939
16th to endDay
14%9%46%425%446%37%
2112
April1st to 15thDay
19%7%25%5%35%447%34%
2190
16th to endDay
25%6%25%323345%36%
2340
May1st to 15thDay
21%8%36%5%25%346%32%
2467
16th to endDay
22%7%35%43335%6%33%
2672
June1st to 15thDay
23%7%35%424446%32%
2700
16th to endDay
24%7%2443445%7%30%
2700
July1st to 15thDay
13%5%245%345%6%9%37%
2700
16th to endDay
16%6%245%345%5%8%36%
2750
August1st to 15thDay
17%414425%45%7%40%
2347
16th to endDay
11%5%25%43446%8%42%
2462
September1st to 15thDay
18%6%25%434347%40%
2157
16th to endDay
17%5%24313346%47%
1953
October1st to 15thDay
17%6%25%5%2445%7%37%
1800
16th to endDay
24%8%35%42335%6%32%
1856
November1st to 15thDay
24%8%36%43445%5%29%
1525
16th to endDay
17%12%6%10%6%35%35%6%22%
1560
December1st to 15thDay
23%12%49%8%45%436%17%
1393
16th to endDay
21%11%6%12%7%45%45%6%16%
1344
January1st to 15thNight
17%11%48%9%46%5%46%20%
2685
16th to endNight
15%10%36%6%47%46%7%27%
2667
February1st to 15thNight
12%13%36%5%46%446%31%
2285
16th to endNight
17%12%47%5%345%4428%
2051
March1st to 15thNight
18%7%36%7%345%5%6%31%
1998
16th to endNight
16%11%46%423335%36%
2112
April1st to 15thNight
22%7%36%5%3445%6%30%
1755
16th to endNight
24%7%35%422245%35%
1620
May1st to 15thNight
21%8%37%5%25%35%5%32%
1484
16th to endNight
22%6%35%4345%5%8%29%
1449
June1st to 15thNight
24%9%35%42346%6%28%
1260
16th to endNight
23%6%36%5%25%447%29%
1260
July1st to 15thNight
15%425%436%5%5%10%36%
1260
16th to endNight
17%6%245%35%5%7%7%33%
1403
August1st to 15thNight
17%5%245%345%5%8%35%
1611
16th to endNight
13%6%25%5%4436%8%39%
1739
September1st to 15thNight
18%6%25%423445%42%
1800
16th to endNight
16%413323445%48%
2007
October1st to 15thNight
18%5%25%5%33446%40%
2160
16th to endNight
25%10%15%5%2345%6%29%
2367
November1st to 15thNight
22%9%36%6%34346%29%
2663
16th to endNight
20%11%5%9%6%34445%22%
2730
December1st to 15thNight
21%13%5%9%7%36%45%6%16%
2648
16th to endNight
23%13%6%8%8%45%445%15%
2880

Transparency (when cloud cover <= 30%)
Color Meanings:
Too cloudy to forecast Poor Below Average Average Above average Transparent
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
62%8%10%11%7%
1254
16th to endDay
50%7%12%20%8%
1555
February1st to 15thDay
50%6%15%20%5%1
1578
16th to endDay
56%5%8%20%8%
1422
March1st to 15thDay
49%412%20%10%2
1950
16th to endDay
48%49%22%12%1
2112
April1st to 15thDay
48%5%10%19%12%2
2190
16th to endDay
49%310%17%14%2
2340
May1st to 15thDay
52%410%19%11%
2467
16th to endDay
51%6%15%17%8%
2676
June1st to 15thDay
52%413%19%10%
2700
16th to endDay
51%7%15%17%7%
2700
July1st to 15thDay
40%7%19%23%8%
2541
16th to endDay
44%7%18%20%7%
2578
August1st to 15thDay
41%8%19%23%6%
2333
16th to endDay
37%7%22%25%6%
2462
September1st to 15thDay
44%6%16%22%10%
2157
16th to endDay
37%415%28%12%
1953
October1st to 15thDay
45%5%17%22%8%
1800
16th to endDay
51%5%12%20%8%
1856
November1st to 15thDay
56%6%13%15%7%
1525
16th to endDay
63%5%13%14%3
1560
December1st to 15thDay
68%6%12%7%4
1393
16th to endDay
69%6%10%11%3
1344
January1st to 15thNight
63%7%10%12%5%
2685
16th to endNight
52%7%11%19%8%
2667
February1st to 15thNight
51%5%13%18%8%1
2286
16th to endNight
58%5%9%16%9%1
2051
March1st to 15thNight
53%5%8%18%12%1
2010
16th to endNight
51%38%19%14%2
2112
April1st to 15thNight
53%48%18%11%2
1755
16th to endNight
50%49%15%17%3
1620
May1st to 15thNight
53%5%9%21%8%1
1484
16th to endNight
52%6%12%20%7%1
1451
June1st to 15thNight
55%5%11%16%9%1
1260
16th to endNight
54%6%15%15%8%
1260
July1st to 15thNight
42%7%14%27%8%
1190
16th to endNight
47%8%16%19%8%
1313
August1st to 15thNight
45%7%17%22%6%
1600
16th to endNight
41%7%18%24%7%
1739
September1st to 15thNight
43%5%11%28%10%
1800
16th to endNight
36%5%15%27%13%1
2007
October1st to 15thNight
45%5%14%24%9%1
2160
16th to endNight
56%410%21%6%
2367
November1st to 15thNight
56%413%17%6%
2663
16th to endNight
63%7%12%13%3
2730
December1st to 15thNight
69%5%9%12%2
2648
16th to endNight
70%6%8%11%3
2880

Seeing (when cloud cover <= 80%)
Color Meanings:
Too cloudy to forecast Bad 1/5 Poor 2/5 Average 3/5 Good 4/5 Excellent 5/5
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
21%16%40%10%11%
60
16th to endDay
15%8%36%28%9%1
163
February1st to 15thDay
18%10%31%28%9%1
236
16th to endDay
23%14%24%23%12%1
212
March1st to 15thDay
19%12%32%24%7%2
270
16th to endDay
20%11%32%21%10%3
288
April1st to 15thDay
26%11%28%21%10%2
270
16th to endDay
27%10%27%21%10%4
270
May1st to 15thDay
28%7%26%20%12%4
423
16th to endDay
28%6%27%25%10%1
519
June1st to 15thDay
29%423%28%11%1
495
16th to endDay
27%425%26%13%3
495
July1st to 15thDay
19%226%30%15%5%
475
16th to endDay
20%220%34%16%4
514
August1st to 15thDay
15%123%32%21%5%
320
16th to endDay
13%7%22%31%18%6%
332
September1st to 15thDay
19%6%30%29%12%1
315
16th to endDay
19%10%28%28%9%3
307
October1st to 15thDay
18%15%29%20%12%4
270
16th to endDay
26%20%27%17%7%1
288
November1st to 15thDay
27%13%27%18%10%1
280
16th to endDay
24%12%34%21%5%1
285
December1st to 15thDay
33%12%30%17%5%
175
16th to endDay
23%28%37%9%1
64
January1st to 15thNight
22%14%35%21%4
750
16th to endNight
20%13%36%23%5%
781
February1st to 15thNight
20%9%36%25%7%
704
16th to endNight
24%11%25%25%10%1
631
March1st to 15thNight
20%9%34%26%7%
720
16th to endNight
22%12%30%23%9%1
768
April1st to 15thNight
26%8%25%28%9%
549
16th to endNight
27%6%27%24%11%1
540
May1st to 15thNight
25%423%29%14%2
540
16th to endNight
22%433%26%11%1
516
June1st to 15thNight
31%218%33%13%1
360
16th to endNight
24%318%36%14%1
360
July1st to 15thNight
15%320%38%18%3
340
16th to endNight
17%323%35%17%2
454
August1st to 15thNight
17%218%37%20%2
539
16th to endNight
15%420%39%17%1
573
September1st to 15thNight
20%7%26%32%11%1
540
16th to endNight
18%7%30%31%11%
717
October1st to 15thNight
19%8%34%26%10%1
720
16th to endNight
29%13%30%20%6%
772
November1st to 15thNight
26%14%27%20%8%1
805
16th to endNight
27%14%27%22%6%1
825
December1st to 15thNight
29%17%31%17%3
769
16th to endNight
31%14%30%16%6%1
800
Page generated at 2017-12-05 11:19:02. Version ac04

Copyright 2017 A. Danko


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